The formal goodbye capped a four-day diplomatic marathon by Charles and Camilla, which is already being cited as going a long way in healing a rift between the two nations.
Highlights of the trip included Charles’ speech on Tuesday to the US Congress, the first by a British monarch since Queen Elizabeth in 1991.
The address was warmly received, even as Charles ranged over subjects such as climate change, the need for restraints on presidential power and the importance of Nato - sensitive issues for Trump’s ruling Republicans.
The royals visited New York on Wednesday, where they stopped at the 9/11 memorial and met leftist Mayor Zohran Mamdani.
Charles, who is passionate about gardening and the environment, later visited an urban sustainable farming project in Harlem, while Camilla celebrated the 100th birthday of Winnie the Pooh at the New York Public Library.
Security has been tight for the royal visit, which came just days after an alleged assassination attempt against Trump at a Washington media gala.
- AFP